Cerebral blood flow in patients with a subarachnoid haemorrhage during treatment with tranexamic acid.

Many clinicians currently use antifibrinolytic therapy (AFT) routinely in the management of subarachnoid haemorrhage (SAH). Many others do not, either because they remain unconvinced that AFT reduces the risk of rebleeding, or that the medication itself causes serious complications and in particular cerebral ischaemia. Nineteen randomly selected patients were studied, 9 receiving tranexamic acid (9 g a day) and the remaining 10 placebo, with SAH confirmed by CT scanning and by lumbar puncture. There was no difference between the active and placebo group regarding the age, sex, clinical grade, CT scan and angiographic appearance. The intravenous Xe133 technique was used for serial determinations of hemispheral cerebral blood flow. The cerebral blood flow remained stable during the first week following subarachnoid haemorrhage, and then fell progressively, reaching its bottom level by the end of the second week. The cerebral blood flow levelled out during the third week at the end of which a sharp elevation, well above the first week's post-subarachnoid haemorrhage level, was noted. This rebound rise of cerebral blood flow was observed for both cerebral hemispheres. Cerebral flow was greatest in the contralateral (to side of ruptured aneurysm) brain hemisphere save for the peak observed during the first week post-subarachnoid haemorrhage. The difference between the ipsi- and contralateral hemispheres was most pronounced in patients receiving active treatment. Analysis of variance showed that cerebral blood flow was reduced by the active treatment and especially more so on the ipsilateral side with the ruptured aneurysm. The usefulness of AFT should therefore be reconsidered.(ABSTRACT TRUNCATED AT 250 WORDS)